In conventional elevators, it is a general practice to electrically connect the control device in a machine room and the car by a traveling cable in order to supply the power for opening and closing the door and for lighting, which are required by the car of an elevator, and the power to each device provided in the car and in order to transmit control signals.
However, because this traveling cable becomes long in a skyscraper elevator installed in a building with a large building height, due to the effects of the weight and swing of the traveling cable itself and the like, troubles such as cutting of the traveling cable may occur. Also, voltage drops increase because of the long traveling cable and, therefore, it is necessary to make the core wires of the traveling cable thick or to increase the number of traveling cables to be used.
Therefore, there is an idea that the supply of power (power supply) to the car and a signal transmission are performed without relying on the traveling cable. The signal transmission can be relatively easily realized by radio transmission and optical transmission.
For the power supply to the car, there has hitherto been known a method which involves providing a power accumulation device, such as a battery, in a car, and accumulating power as required in each device of the car via a power conversion device, such as an inverter, from this power accumulation device, providing a power supply device on each service floor of the elevator, and from this power supply device, performing the charging of the power accumulation device as required via a power conversion device, such as a converter, while the elevator is stopped.
For conventional car power supply devices of an elevator, in an elevator in which a car and a counterweight are hung in a shaft in such a manner as to be able to ascend and descend in a well-bucket manner along each guide rail via a main rope wound and suspended on a sheave in the upper part of the shaft and a drive unit for ascent and descent is provided in either or both of the car and the counterweight, there is known another car power supply device in which a power transmission line which permits power transmission between the above-described car and the above-described counterweight is provided so as to pierce through the above-described main rope, a power supply line which supplies power only to either the above-described car or the above-described counterweight is provided, and by using this power supply line and the above-described power transmission line between the main rope, power supply is performed to the above-described drive unit for ascent and descent and the car-side electrical equipment such as lighting (refer to Patent Literature 1, for example).
And as a car power supply device which performs power supply from power supply means to power receiving means in the power supply to a car and a counterweight in a noncontact manner, there is known, for example, a car power supply device in which a power supply device is provided in a position opposed to the position of the counterweight in the case where a car in a shaft is stopped at a standard floor, the counterweight is provided with power receiving means which receives the power from this power supply device in a noncontact manner, an inverter and a motor which drives the counterweight vertically, and on the basis of positions detected by means which detects the positions of the above-described power supply device and the above-described power receiving means, the counterweight is driven so that the above-described power receiving means is opposed to the above-described power supply device (refer to Patent Literature 2, for example).